Quick Tip

Master `diff` with Process Substitution for Inline Comparisons

Challenge: Comparing two complex or dynamically generated outputs directly on the command line can be cumbersome, often requiring temporary files.

The Solution: Utilize Bash’s process substitution to feed the output of two commands directly into `diff` without creating intermediate files.

diff <(command1) <(command2)

Why it works: Process substitution (`<(…)`) treats the output of a command as if it were a file, allowing `diff` to operate on these “virtual files” directly. This avoids the overhead and potential clutter of temporary file creation.

Pro-Tip: This technique is incredibly useful for comparing configuration files generated by different tools or for debugging scripts that produce varying outputs.

Linux Tips & Tricks | © ngelinux.com | 4/26/2026